Multi-layered repair patches are known in the art and these repair patches have been used both for repairing holes in drywall material as well as repairing holes in automobile bodies. U.S. Pat. Nos. 5,075,149 issued to Owens et al. ("Owens"), 4,707,391 issued to Hoffmann ("Hoffmann '391") and 4,135,017 issued to Hoffmann ("Hoffmann '017") are all directed to multi-layer repair patches.
Owens discloses a three-layered patch with a metal plate disclosed between two polyester sheets. The metal plate is held in place between the two polyester sheets with a semi-solid adhesive such as urethane. The semi-solid adhesive fixedly attaches the two polyester sheets together as well as fixedly attaching the reinforcing metal plate between the two sheets. Owens is not useful for repairs which require the application of bonding material or plaster to the repair patch because the bonding material or plaster cannot readily pass through the mesh due to the presence of the urethane adhesive.
Hoffmann '391 discloses a two-layer patch including a perforated metal plate with an outer fiberglass mesh attached to one side of the plate. A glue or adhesive coating is applied to the surface of the plate that is attached to the surface to be repaired and an additional adhesive coating is applied to the inward-facing surface of the fiberglass mesh to attach the mesh to the metal plate as well as to attach the mesh to the surface under repair.
Hoffmann '017 also discloses a two-layer patch. An inner metal plate is covered with adhesive that secures one surface of the plate to the surface under repair. An outer plate cover is laminated onto the exterior side of the metal plate by means of a layer of adhesive applied to the inward-facing side of the plate cover.
In addition to disclosing multi-layered patches, Owens, Hoffmann '391 and Hoffmann '017 share at least one feature. Specifically, all three references teach the application of glue or adhesive to the reinforcing sheet or plate, which is most commonly a piece of thin metal. The application of adhesive to a metal sheet is a costly manufacturing process. Specifically, glues applied to metal sheets must be cured for fifteen to forty-five minutes thereby substantially slowing down the manufacturing process. Further, metal sheeting is not available with glue or adhesive already applied to it. The patch manufacturer must therefore apply the glue or adhesive during the assembly process.
Accordingly, there is a need for a multi-layer patch design with an adhesive-free reinforcing sheet that also allows bonding material, plaster or drywall mud to pass through the repair patch. By providing an adhesive-free reinforcing sheet, the multi-layer patch would be substantially faster and cheaper to manufacture. The result will lower the cost of multi-layer repair patches to the consuming public and therefore broaden the application of multi-layer repair patches.